ok

I've had dozens of buddies and people that I know go the officer route, and a few folks go enlisted. I'm eventually going in myself.

There's two things you have to look at here:
1) Will your herniated disk affect your ability to accomplish the mission and protect your fellow Marines
2) Can you find an MOS that, even if the Marine knew about your herniated disk, would give you a medical waiver because the chances of it affecting your job would be minimal to none

There are certain things that, if their physical can't find it, you don't tell them about it. On the other hand, something like a herniated disk, I'm not so sure you want to keep something like that from them.

I found this online, dont know if it helps:

Sixty-six consecutive active duty military personnel with herniated lumbar intervertebral discs were treated by open surgical discectomy. Of these patients, 54 (82%) had relief of their radiating leg pain and were able to return to full duty status. The other 12 patients (18%) were unable to return to full duty because of either persistent postoperative radiating leg pain or low back pain. Open surgical discectomy is an effective treatment modality for lumbar disc herniations in a military population with a vigorous life-style mandated by their active duty status.
im a newbie so it wont let me post links, but url is doubleudoubleudoubledot
ncbi.nlm.nih.gov/pubmed/2507963

Bottom line is there are people in the military with a history of a disc issue.